Differential pressure transmitters are used primarily in flow applications in concert with a measuring element such as an orifice plate, pitot tube, or V-Cone type sensor. These devices measure the difference between 2 pressures and provide a linear or square root analog output signal in proportion to the difference. DP transmitters are also used in level and low gauge pressure applications where the pressure inside a duct or the level of fluid inside a tank can be compared to atmospheric pressure. Vacuum & compound range applications should be limited to where the vacuum value is less than 30” water column vacuum.
Smart transmitters have the benefit of adjustable measuring span or range within specified limits. These units can be re-ranged in the field or instrument shop with hand-held communication tools and/or pressure standards. To select the appropriate model, determine the pressure range of the media being measured, identify the temperature of the media being measured, understand the corrosive nature of the media, and consider the mounting of the unit for practical installation, calibration and maintenance of the unit